Arrow Electrical System Presented by Michelle Crocco

Overview Importance of knowing the electrical system Components Alternator Battery Voltage Regulator Overvoltage Relay Ammeter Circuit Breakers Emergencies Review

Importance The Piper Arrow will be used during your commercial and flight instructor check ride As PIC, it is important to know different components of your aircraft

Alternator Serves as the primary electrical source 14 volt, 60 amps A rotating electromagnet connected to the crankshaft generates AC power Rectifiers rectify AC to DC power A small discharge from the battery is needed to excite the alternator

Battery Serves as the secondary source of power 12 volt, 35 amps Uses: Used for engine start up Back-up in case of alternator failure

Voltage Regulator Basic Definition: it acts like a funnel only allowing so much current through the system and regulating the system voltage Maintains the system voltage to 11-14 volts It is located on the left side of the firewall

Overvoltage Relay Controls the alternator so it doesn’t put out too much voltage Takes the alternator off if it exceeds 17 volts

Ammeter Indicates the load (in amps) on the system

Circuit Breakers They protect individual electrical components If a current flow is too high, the circuit trips and the circuit is opened. This does not allow current to flow to the specific component.

Emergencies Includes an annunciator panel with alternator, low oil pressure, and low vacuum indicator lights Serves only as a warning to pilots Follow the appropriate checklist

Review How many volts and amps is the alternator? The battery? What does an voltage regulator act like? What 3 indications are included in the annunciator panel?